what's the difference between NSManagedObjectContext reset and rollback?

Question

The documentation says:

- (void)reset

Returns the receiver to its base state.

Discussion

All the receiver\'s man

Answer 1

The key part is in the quote

All the receiver's managed objects are “forgotten”.

- (void)reset; will give you a clean NSManagedObjectContext with no objects in it and as the docs state any NSManagedObject's you have around should be discarded as they are no longer valid.

- (void)rollback will just restore the NSManagedObject's to their persisted values

Answer 2

-reset is different than -rollback in that it invalidates any NSManagedObjects that have been fetched from the context. Attempting to use those objects can be expected to throw an exception. However -rollback simply discards unsaved changes.